The JAM Pedals "Luminous" Fuzz Phrase Si is a silicon fuzz pedal, part of JAM's Luminous range of hand-painted pedals. Where the original Fuzz Phrase uses germanium transistors, the Si version is built around BC107 silicon transistors: JAM says that after meticulous testing of various silicon transistors, "the BC107s emerged as the unequivocal choice," and that the circuit was then fine tuned to them1. It is a compact, low-draw pedal that runs from a battery or a standard 9V adaptor.
Controls
The Fuzz Phrase Si keeps its control layout simple, with two knobs on the surface and one trimmer inside1:
| Control | What it does |
|---|---|
| Gain | Sets the amount of gain1 |
| Level | Adjusts output volume, while also allowing for versatile tonal shaping1 |
| Internal Trimmer | Sets transistor bias, factory-set at 4.5V1 |
The internal trimmer is worth knowing about: it sets the transistor bias and leaves the factory at 4.5V, so the pedal is dialed in before it ships and most players will leave it alone1.
Power and size
The pedal works with a 9V battery or a 9V DC adaptor with a tip-negative plug, and JAM lists power consumption at 3 mA1. That is a light draw, so it presents no problem for a shared power supply output. At 7.5 x 12 x 5.6 cm and 250g, it is a standard compact enclosure that fits a crowded board without crowding its neighbors1.
The adaptor polarity is tip-negative, which is the common standard for guitar pedals, but it is the opposite of some synth and rack gear supplies. Use a center-negative style 9V supply as JAM specifies.
The Luminous artwork versions
The Luminous range is defined by its custom artwork. JAM offers the Fuzz Phrase Si in several hand-painted versions, all with the same circuit and sound1:
JAM describes these as "Same sound, different artwork"1, so the choice between them is purely visual. Each one is a one-of-a-kind hand-painted piece, and the maker states that the pedal you receive will differ in detail from the photos shown1.
Si versus germanium
The Fuzz Phrase family splits by transistor type. The Si version covered here uses BC107 silicon transistors, while the germanium Fuzz Phrase remains a separate pedal in the range, alongside the limited-edition germanium versions such as the Black Fuzz Phrase LTD. Silicon and germanium fuzzes respond differently to temperature and supply, and players generally choose between them by taste; JAM's own account of the Si is that it tested various silicon transistors and fine tuned the circuit to the BC107s it settled on1. If you are exploring the maker's fuzz range more broadly, the Eureka, Red Muck and Black Muck cover other fuzz territory, and the Octaurus adds an octave to the fuzz. For the wider picture, see Fuzz Pedals.
Buying direct
JAM sells the Fuzz Phrase Si through its own webstore at a regular price of £294.00 GBP, tax included1. The maker offers a 30-day money-back guarantee with a refund, no questions asked, if you are not satisfied after receiving the product1. For UK buyers, JAM states that orders ship DDP with 20% UK VAT and all duties included, with no extra charges on delivery1.
Questions
Is the JAM Pedals Fuzz Phrase Si true bypass?
Yes. JAM Pedals lists the Fuzz Phrase Si as true bypass, so when the pedal is off your guitar's signal passes to the rest of the board without going through the fuzz circuit. It runs on a 9V battery or a 9V DC adaptor with a tip-negative plug and draws 3 mA, which is light enough for almost any pedalboard power supply.
How much current does the Fuzz Phrase Si draw?
JAM Pedals lists power consumption at 3 mA. The pedal runs on a 9V battery or a 9V DC adaptor with a tip-negative plug. That draw is low by pedal standards, so it sits comfortably on a shared power supply output alongside other low-draw pedals.
How does the Fuzz Phrase Si differ from the germanium Fuzz Phrase?
The Si version uses BC107 silicon transistors instead of the germanium devices in the original Fuzz Phrase. JAM Pedals says it tested various silicon transistors and the BC107s emerged as its choice, with the circuit then fine tuned to them. The germanium original remains a separate pedal in the company's range.
Will my Luminous pedal look exactly like the photos?
No. Every custom artwork pedal in the Luminous range is a one-of-a-kind hand-painted piece, and JAM Pedals states plainly that the pedal you receive will differ in detail from the photos shown. The artwork style you pick, such as Relic or Mandala, is what you get, but the exact paintwork is unique to your unit.
Sources (1)
- “Luminous” Fuzz Phrase Si, JAM Pedals (jampedals.com)
